Space station and satellites to present light show

The International Space Station and a pair of communications satellites will put on a celestial show for early risers in the days around Christmas if the clouds cooperate.

At 6:21 a.m. Saturday the Iridium-3 satellite will flare high in the north, near the “pointer stars” of the Big Dipper. This will be by far the brightest object in the sky, even though Jupiter and Mars will be high in the southeast, just above the constellation Scorpius.

Two stars in Ursa Major, Dubhe and Merak, point to the North Star, aka Polaris and Hokupa‘a. The Iridium-3 flare will be in the other direction, about the same distance away as the distance between the stars.

An even brighter flare will occur Sunday, just past 6:15 a.m. in nearly the same spot, when sunlight catches the antennas of the Iridium- 76 satellite.

Just a few minutes later, at 6:34 a.m., the space station will rise in the southwest and angle high and to the left. It will pass high above Mars, Jupiter and, lower on the horizon, Mercury at 6:38 a.m.

A few seconds later it will pass above the bright star Arcturus, or Hokule‘a. It will then descend toward the northeastern horizon, blinking out in Earth’s shadow at about 6:40, just left of the bright star Vega.

On Monday the space station will rise in the south-southwest at about 5:43 a.m. and angle low and to the left. It will pass just below Mars and Jupiter a few seconds before 5:46 a.m.

It will disappear in the northeast about two minutes later.

Those with a clear view of the southern horizon will be able to see the Southern Cross at that hour.

At about 6:27 a.m. Tuesday the space station will rise in the west-southwest and move to the right. It will thread between Castor and Pollux, the twin stars of Gemini, about two minutes later.

It will pass just under the North Star a few seconds after 6:31 a.m. before blinking out of sight.

The space station is visible just before dawn and just after dusk when it is illuminated by the sun against the darker sky. Currently 254 miles up, the space station orbits at a speed of 17,130 mph, taking it around the planet roughly every 90 minutes.

Aboard are Americans Randy Bresnik, Joe Acaba and Mark Vande Hei; two Russians; and an Italian.